Thromboembolism, as a potentially lethal complication especially occured in pulmonary arteries, is uncommon in patients undergone arthroscopy. We describe a case of pulmonary thromboembolism that accurred after a diagnostic knee arthroscopy under spinal anesthesia with the isobaric tetracaine. Cardiopulmonary collapse occurred suddenly on the postoperative 2nd day and resuscitation was unsuccessful. Definitive diagnosis was made at autopsy. On the review of literatures, two cases of thromboembolism following arthroscopy under spinal anesthesia have been previously reported, but fatal case has not.